Brake for fire-shutters



E. H. MccIIouD. BRAKE FOR FIRE `HUTTERS. APPLICATION FILED .IUNE29, ISIB- lPmnwd May 4,1920.;

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a I.II II UNITED STATES PATENT OFFICE.

EDWARD H. MOCLOUD, OF COLUMBUS, OHIO, ASSIGNOR TO THE KINNEAR MANUFAC- TUBING- COMPANY, OF COLUMBUS, OHIO, A'GORPORATION 0F OHIO.

BRAKE FOR FIRE-SHUTTERS.

Specification of Letters Patent.

Patented May 4, 1920.

original application filed July ze, 1915, ariane-11,532. Patented August e, 191s, No. 1,275,168. Divided and this application filed .Tunev29, 1918. Serial No.v 242,609. f

To all whom t may concern Be it known that I, EDWARD I'I. McCLoD, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have .invented a certain new and useful Improvement in Brakes for Fire- Shutters, of which the following is a speciication. v

This invention relates more particularly to centrifugal brakes especially designed for use in connection with automatically closing shutters and the invention has for its principal object to provide an improved construction of such a brake adapted to operate when the curtain is automatically released for closing as in the event of nearby fire.

The invention is embodied in the example shown in the accompanying drawing and set forth in the following specification.

In said drawing- Figure 1 is an end view in elevation with parts broken out showing the brake set to permit ordinary operation of the shutter.

Fig. 2 is a front View.

Fig. 3 is an end view in elevation illustrating the brake released for operation.

Fig. 4 is a sectional view.

Fig. 5 is a detail of the brake members.

In the views 6 designates one end of the curtain roller and 7 a bracket for supporting the shaft 8 of said end of the curtain roller. Secured to the end of the shaft 8 where it projects beyond the bracket and to rotate with the shaft is a ratchet wheel 9 having a hub sleeve 10. Loose on said sleeve is a spur gear wheel 11 carrying a pawl 12 pivoted so as to be capable of engaging a tooth of the ratchet. Said pawl has an extended heel 13.

Journaled on a suitable bearing 14 extending from the bracket below the spur gear 11 is a pinion 15 having fixed therewith a cross plate or frame to the opposite ends of which are loosely pivoted on pins 16 two brake shoes 17. The shoes 17 have inward projections 17 a at their free ends. Also pivoted on said pins 16 are arms or levers 18 having cams 18a near their pivots and weighted portions 18b at their free ends. The cams 18a are located to press, when turned outward, upon the projections 17 a at the free ends of the shoes. Springs 19 connect the arms 18 with the pins 16, said springs tending normally to hold the cam 18 out of engagement with the projections 17.

.Mounted in bracket is a weighted lever 2O having connected with its inner end a short arm or dog 21 arranged so that when the weight lever 20 is elevated to horizontal position it extends into the path of the heel 13 and holds the pawl 12 disengaged from the ratchet 9. The lever 20 is held elevated by means ofa wire 22 containing a portion 23, fusible by a dangerous rise of temperature, said wire being secured to a suitable fixed point above.

When the parts are arranged, as shown lin Fig. 1, the shaft of the roller is free to turn without operating the brake at all.- When the weight lever 2() is released, as by a nearby fire, the pawl is thrown into engagement with the ratchet 9 and the gear wheel 11 caused to rotate with the shaft of the roller. Rotation of the gear wheel 11, of course, causes rotation of the pinion 15, and the impulsion outward by centrifugal force of the brake shoes and the arms 18 with the cam 18, The pressure of the cams 18a on the brake shoes, because on the extremities of the shoes insures a tight bearing ofthe shoes against the brake rim 24. The brake rim 24 is conveniently formed in an extension of a suitable hood 25 for the brake mechanism.

In the normal position of the parts, which is that shown in Fig. 1, the shutter or curtain attached to the roller can be rolled up and unrolled as desired without operating the brake at all, because the shaftvS of the shutter and the ratchet wheel 9 attached thereto run idly in the spur gear 11. When, however, the pawl-12 is released as by the melting of the fusible portion or member 23 and thelever arm 20 drops the pawl 12 swings into engagement with the ratchet wheel 9 and thus operatively unites the shaft with said spur gear wheel 11 and causes it to turn and through it the pinion 15. The rapid rotation of the pinion 15 throws out the brake shoes 17 as well as the arms 18, and the cams 181 thereof acting on the free ends of the shoes, as illustrated in Fig. 2, engender a firm and extensive pressure of the shoes 17 on the brake rim 24 tending to prevent a too rapid unwinding of the curtain. It will be understood, of course, that where the curtain is one that is counterbalanced for raising and lowering in normal circumstances that thermally actuated means like that at 22-23 will be provided for liberating the counterbalancing means in case of lire and that such means can be arranged in position to operate simultaneously or nearly simultaneously with the means for releasing the brake. Indeed the same means7 22-28, can be used to hold the counterbalancing spring latched from action.

The number and forms of the parts can be changed Without departing from the gist of the invention as claimed.

The application for this patent of the United States is a division of an application for patent filed by me on July 23, 1915, S. No. L11,532, patented August 6, 1918, No. 1,27 5,168.

That I claim is- Y 1. A brake mechanism including, in combination, a brake rim, two opposingly arranged shoes to engage said rim, each of said shoes being pivoted at one end on a pivot Within said rim, a centrifugally actuated arm carrying a cam pivoted on'the pivot of each of saidvshoes, the cam on the pivot of one shoe acting on the free end of ranged shoes to engage said rim, each of 'saidA shoes being pivoted at one .end on a pivot Within said rim, a lcentrifugally actuated arm carrying a cam pivoted on the pivot of each of said shoes, the cam on the pivot of one shoe acting on the free end of the other slice to aid centrifugal action thereof on the brake rim, and a spring connecting the pivot of each shoe With the arm carrying the cam actuating it, said spring tending to Withdraw said cam from operation when centrifugal action ceases.

EDWARD H. MCCLOUD. 

